Mass spectrograph A stream of particles of various masses, all carrying the same charge e, is moving along the x-axis in the positive x-direction. When the particles reach the origin they encounter an electronic `gate' which allows only those particles with a specified speed V to pass. These particles then move in a uniform magnetic field B0 acting in the z-direction. Show that each particle will execute a semicircle before meeting the y-axis at a point which depends upon its mass. [This provides a method for determining the masses of the particles.]